/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.db.engine.load;

import org.apache.iotdb.common.rpc.thrift.TTimePartitionSlot;
import org.apache.iotdb.db.utils.TimePartitionUtils;
import org.apache.iotdb.tsfile.common.conf.TSFileConfig;
import org.apache.iotdb.tsfile.exception.write.PageException;
import org.apache.iotdb.tsfile.exception.write.UnSupportedDataTypeException;
import org.apache.iotdb.tsfile.file.header.ChunkHeader;
import org.apache.iotdb.tsfile.file.header.PageHeader;
import org.apache.iotdb.tsfile.file.metadata.IChunkMetadata;
import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.file.metadata.statistics.Statistics;
import org.apache.iotdb.tsfile.read.common.Chunk;
import org.apache.iotdb.tsfile.utils.*;
import org.apache.iotdb.tsfile.write.chunk.AlignedChunkWriterImpl;
import org.apache.iotdb.tsfile.write.schema.IMeasurementSchema;
import org.apache.iotdb.tsfile.write.schema.MeasurementSchema;
import org.apache.iotdb.tsfile.write.writer.TsFileIOWriter;

import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.Serializable;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;

public class AlignedChunkData implements ChunkData {
    private static final int DEFAULT_INT32 = 0;
    private static final long DEFAULT_INT64 = 0L;
    private static final float DEFAULT_FLOAT = 0;
    private static final double DEFAULT_DOUBLE = 0.0;
    private static final boolean DEFAULT_BOOLEAN = false;
    private static final Binary DEFAULT_BINARY = null;

    private final TTimePartitionSlot timePartitionSlot;
    private final String device;
    private List<ChunkHeader> chunkHeaderList;

    private final PublicBAOS byteStream;
    private final DataOutputStream stream;
    private List<long[]> timeBatch;
    private long dataSize;
    private boolean needDecodeChunk;
    private List<Integer> pageNumbers;
    private Queue<Integer> satisfiedLengthQueue;

    private AlignedChunkWriterImpl chunkWriter;
    private List<Chunk> chunkList;

    public AlignedChunkData(
            String device, ChunkHeader chunkHeader, TTimePartitionSlot timePartitionSlot) {
        this.dataSize = 0;
        this.device = device;
        this.chunkHeaderList = new ArrayList<>();
        this.timePartitionSlot = timePartitionSlot;
        this.needDecodeChunk = true;
        this.pageNumbers = new ArrayList<>();
        this.satisfiedLengthQueue = new LinkedList<>();
        this.byteStream = new PublicBAOS();
        this.stream = new DataOutputStream(byteStream);

        chunkHeaderList.add(chunkHeader);
        pageNumbers.add(0);
        addAttrDataSize();
    }

    private void addAttrDataSize() { // should be init before serialize, corresponding serializeAttr
        dataSize += 2 * Byte.BYTES; // isModification and isAligned
        dataSize += Long.BYTES; // timePartitionSlot
        int deviceLength = device.getBytes(TSFileConfig.STRING_CHARSET).length;
        dataSize += ReadWriteForEncodingUtils.varIntSize(deviceLength);
        dataSize += deviceLength; // device
        dataSize += Integer.BYTES; // chunkHeaderListSize
        dataSize += chunkHeaderList.get(0).getSerializedSize(); // timeChunkHeader
    }

    @Override
    public String getDevice() {
        return device;
    }

    @Override
    public TTimePartitionSlot getTimePartitionSlot() {
        return timePartitionSlot;
    }

    @Override
    public long getDataSize() {
        return dataSize;
    }

    @Override
    public void setNotDecode() {
        needDecodeChunk = false;
    }

    @Override
    public boolean isAligned() {
        return true;
    }

    @Override
    public void writeToFileWriter(TsFileIOWriter writer) throws IOException {
        if (chunkList != null) {
            for (Chunk chunk : chunkList) {
                writer.writeChunk(chunk);
            }
        } else {
            chunkWriter.writeToFileWriter(writer);
        }
    }

    public void addValueChunk(ChunkHeader chunkHeader) {
        this.chunkHeaderList.add(chunkHeader);
        this.pageNumbers.add(0);
        dataSize += chunkHeader.getSerializedSize();
        if (needDecodeChunk) {
            dataSize += Integer.BYTES; // pageNumber
        }
    }

    @Override
    public void serialize(DataOutputStream stream) throws IOException {
        ReadWriteIOUtils.write(isModification(), stream);
        ReadWriteIOUtils.write(isAligned(), stream);
        serializeAttr(stream);
        byteStream.writeTo(stream);
        close();
    }

    private void serializeAttr(DataOutputStream stream) throws IOException {
        ReadWriteIOUtils.write(timePartitionSlot.getStartTime(), stream);
        ReadWriteIOUtils.write(device, stream);
        ReadWriteIOUtils.write(needDecodeChunk, stream);
        ReadWriteIOUtils.write(chunkHeaderList.size(), stream);
        for (ChunkHeader chunkHeader : chunkHeaderList) {
            chunkHeader.serializeTo(stream); // chunk header already serialize chunk type
        }
        if (needDecodeChunk) {
            for (Integer pageNumber : pageNumbers) {
                ReadWriteIOUtils.write(pageNumber, stream);
            }
        }
    }

    @Override
    public void writeEntireChunk(ByteBuffer chunkData, IChunkMetadata chunkMetadata)
            throws IOException {
        dataSize += ReadWriteIOUtils.write(chunkData, stream);
        dataSize += chunkMetadata.getStatistics().serialize(stream);
    }

    @Override
    public void writeEntirePage(PageHeader pageHeader, ByteBuffer pageData) throws IOException {
        pageNumbers.set(pageNumbers.size() - 1, pageNumbers.get(pageNumbers.size() - 1) + 1);
        dataSize += ReadWriteIOUtils.write(false, stream);
        dataSize += pageHeader.serializeTo(stream);
        dataSize += ReadWriteIOUtils.write(pageData, stream);
    }

    @Override
    public void writeDecodePage(long[] times, Object[] values, int satisfiedLength)
            throws IOException {
        pageNumbers.set(pageNumbers.size() - 1, pageNumbers.get(pageNumbers.size() - 1) + 1);
        satisfiedLengthQueue.offer(satisfiedLength);
        long startTime = timePartitionSlot.getStartTime();
        long endTime = startTime + TimePartitionUtils.getTimePartitionInterval();
        dataSize += ReadWriteIOUtils.write(true, stream);
        dataSize += ReadWriteIOUtils.write(satisfiedLength, stream);

        for (int i = 0; i < times.length; i++) {
            if (times[i] < startTime) {
                continue;
            } else if (times[i] >= endTime) {
                break;
            }
            dataSize += ReadWriteIOUtils.write(times[i], stream);
        }
    }

    public void writeDecodeValuePage(long[] times, TsPrimitiveType[] values, TSDataType dataType)
            throws IOException {
        pageNumbers.set(pageNumbers.size() - 1, pageNumbers.get(pageNumbers.size() - 1) + 1);
        long startTime = timePartitionSlot.getStartTime();
        long endTime = startTime + TimePartitionUtils.getTimePartitionInterval();
        int satisfiedLength = satisfiedLengthQueue.poll();
        dataSize += ReadWriteIOUtils.write(true, stream);
        dataSize += ReadWriteIOUtils.write(satisfiedLength, stream);
        satisfiedLengthQueue.offer(satisfiedLength);

        for (int i = 0; i < times.length; i++) {
            if (times[i] < startTime) {
                continue;
            } else if (times[i] >= endTime) {
                break;
            }

            if (values[i] == null) {
                dataSize += ReadWriteIOUtils.write(true, stream);
                continue;
            }
            dataSize += ReadWriteIOUtils.write(false, stream);
            switch (dataType) {
                case INT32:
                    dataSize += ReadWriteIOUtils.write(values[i].getInt(), stream);
                    break;
                case INT64:
                    dataSize += ReadWriteIOUtils.write(values[i].getLong(), stream);
                    break;
                case FLOAT:
                    dataSize += ReadWriteIOUtils.write(values[i].getFloat(), stream);
                    break;
                case DOUBLE:
                    dataSize += ReadWriteIOUtils.write(values[i].getDouble(), stream);
                    break;
                case BOOLEAN:
                    dataSize += ReadWriteIOUtils.write(values[i].getBoolean(), stream);
                    break;
                case TEXT:
                    dataSize += ReadWriteIOUtils.write(values[i].getBinary(), stream);
                    break;
                default:
                    throw new UnSupportedDataTypeException(
                            String.format("Data type %s is not supported.", dataType));
            }
        }
    }

    private void deserializeTsFileData(InputStream stream) throws IOException, PageException {
        if (needDecodeChunk) {
            buildChunkWriter(stream);
        } else {
            deserializeEntireChunk(stream);
        }
    }

    private void deserializeEntireChunk(InputStream stream) throws IOException {
        chunkList = new ArrayList<>();
        int chunkSize = chunkHeaderList.size();
        for (int i = 0; i < chunkSize; i++) {
            ByteBuffer chunkData =
                    ByteBuffer.wrap(ReadWriteIOUtils.readBytesWithSelfDescriptionLength(stream));
            Statistics<? extends Serializable> statistics =
                    Statistics.deserialize(stream, chunkHeaderList.get(i).getDataType());
            chunkList.add(new Chunk(chunkHeaderList.get(i), chunkData, null, statistics));
        }
    }

    private void buildChunkWriter(InputStream stream) throws IOException, PageException {
        List<IMeasurementSchema> measurementSchemaList = new ArrayList<>();
        for (ChunkHeader chunkHeader : chunkHeaderList) {
            if (TSDataType.VECTOR.equals(chunkHeader.getDataType())) {
                continue;
            }
            measurementSchemaList.add(
                    new MeasurementSchema(
                            chunkHeader.getMeasurementID(),
                            chunkHeader.getDataType(),
                            chunkHeader.getEncodingType(),
                            chunkHeader.getCompressionType()));
        }
        chunkWriter = new AlignedChunkWriterImpl(measurementSchemaList);
        timeBatch = new ArrayList<>();
        int chunkHeaderSize = chunkHeaderList.size();
        for (int i = 0; i < chunkHeaderSize; i++) {
            buildChunk(stream, chunkHeaderList.get(i), pageNumbers.get(i), i - 1, i == 0);
        }
        timeBatch = null;
    }

    private void buildChunk(
            InputStream stream,
            ChunkHeader chunkHeader,
            int pageNumber,
            int valueChunkIndex,
            boolean isTimeChunk)
            throws IOException, PageException {
        boolean needDecode;
        int decodePageIndex = 0;
        for (int j = 0; j < pageNumber; j++) {
            needDecode = ReadWriteIOUtils.readBool(stream);
            if (needDecode) {
                int length = ReadWriteIOUtils.readInt(stream);
                long[] timePageBatch = new long[length];
                if (!isTimeChunk) {
                    timePageBatch = timeBatch.get(decodePageIndex);
                }
                for (int i = 0; i < length; i++) {
                    if (isTimeChunk) {
                        long time = ReadWriteIOUtils.readLong(stream);
                        timePageBatch[i] = time;
                        chunkWriter.writeTime(time);
                    } else {
                        boolean isNull = ReadWriteIOUtils.readBool(stream);
                        switch (chunkHeader.getDataType()) {
                            case INT32:
                                int int32Value = isNull ? DEFAULT_INT32 : ReadWriteIOUtils.readInt(stream);
                                chunkWriter.write(timePageBatch[i], int32Value, isNull, valueChunkIndex);
                                break;
                            case INT64:
                                long int64Value = isNull ? DEFAULT_INT64 : ReadWriteIOUtils.readLong(stream);
                                chunkWriter.write(timePageBatch[i], int64Value, isNull, valueChunkIndex);
                                break;
                            case FLOAT:
                                float floatValue = isNull ? DEFAULT_FLOAT : ReadWriteIOUtils.readFloat(stream);
                                chunkWriter.write(timePageBatch[i], floatValue, isNull, valueChunkIndex);
                                break;
                            case DOUBLE:
                                double doubleValue = isNull ? DEFAULT_DOUBLE : ReadWriteIOUtils.readDouble(stream);
                                chunkWriter.write(timePageBatch[i], doubleValue, isNull, valueChunkIndex);
                                break;
                            case BOOLEAN:
                                boolean boolValue = isNull ? DEFAULT_BOOLEAN : ReadWriteIOUtils.readBool(stream);
                                chunkWriter.write(timePageBatch[i], boolValue, isNull, valueChunkIndex);
                                break;
                            case TEXT:
                                Binary binaryValue = isNull ? DEFAULT_BINARY : ReadWriteIOUtils.readBinary(stream);
                                chunkWriter.write(timePageBatch[i], binaryValue, isNull, valueChunkIndex);
                                break;
                            default:
                                throw new UnSupportedDataTypeException(
                                        String.format("Data type %s is not supported.", chunkHeader.getDataType()));
                        }
                    }
                }
                if (isTimeChunk) {
                    timeBatch.add(timePageBatch);
                }
                decodePageIndex += 1;

                if (isTimeChunk) {
                    chunkWriter.sealCurrentTimePage();
                } else {
                    chunkWriter.sealCurrentValuePage(valueChunkIndex);
                }
            } else {
                PageHeader pageHeader = PageHeader.deserializeFrom(stream, chunkHeader.getDataType(), true);
                if (isTimeChunk) {
                    chunkWriter.writePageHeaderAndDataIntoTimeBuff(
                            ByteBuffer.wrap(ReadWriteIOUtils.readBytesWithSelfDescriptionLength(stream)),
                            pageHeader);
                } else {
                    chunkWriter.writePageHeaderAndDataIntoValueBuff(
                            ByteBuffer.wrap(ReadWriteIOUtils.readBytesWithSelfDescriptionLength(stream)),
                            pageHeader,
                            valueChunkIndex);
                }
            }
        }
    }

    public static AlignedChunkData deserialize(InputStream stream) throws IOException, PageException {
        TTimePartitionSlot timePartitionSlot =
                TimePartitionUtils.getTimePartition(ReadWriteIOUtils.readLong(stream));
        String device = ReadWriteIOUtils.readString(stream);
        boolean needDecodeChunk = ReadWriteIOUtils.readBool(stream);
        int chunkHeaderListSize = ReadWriteIOUtils.readInt(stream);
        List<ChunkHeader> chunkHeaderList = new ArrayList<>();
        for (int i = 0; i < chunkHeaderListSize; i++) {
            byte chunkType = ReadWriteIOUtils.readByte(stream);
            chunkHeaderList.add(ChunkHeader.deserializeFrom(stream, chunkType));
        }
        List<Integer> pageNumbers = new ArrayList<>();
        if (needDecodeChunk) {
            for (int i = 0; i < chunkHeaderListSize; i++) {
                pageNumbers.add(ReadWriteIOUtils.readInt(stream));
            }
        }

        AlignedChunkData chunkData =
                new AlignedChunkData(device, chunkHeaderList.get(0), timePartitionSlot);
        chunkData.needDecodeChunk = needDecodeChunk;
        chunkData.chunkHeaderList = chunkHeaderList;
        chunkData.pageNumbers = pageNumbers;
        chunkData.deserializeTsFileData(stream);
        chunkData.close();
        return chunkData;
    }

    private void close() throws IOException {
        byteStream.close();
        stream.close();
    }

    @Override
    public String toString() {
        return "AlignedChunkData{"
                + "timePartitionSlot="
                + timePartitionSlot
                + ", device='"
                + device
                + '\''
                + ", chunkHeaderList="
                + chunkHeaderList
                + ", totalDataSize="
                + dataSize
                + ", needDecodeChunk="
                + needDecodeChunk
                + '}';
    }
}
